<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
        body>*{
            width: 95%;
            height: auto;
            margin: 0 auto;
            margin-top: 10px;
            border: 1px solid #000;
            padding: 5px;
        }
        header{
            height: 50px;
        }
        section{
            height: 300px;
        }
        footer{
            height: 30px;
        }
        section>*{
            height: 100%;
            border: 1px solid #000;
            float: left;
        }
        aside{
            width: 25%;
        }
        article{
            width: 70%;
            margin-left: 1%;
        }
    </style>
</head>
<body>
    <header>header</header>
    <nav>nav</nav>
    <section>
        <aside>aside</aside>
        <article>article</article>
    </section>
    <footer>footer</footer>
</body>
</html>